As is well known by the consumer, the cost of meat and meat-based products is continually rising. The rising costs have forced many people to modify their nutritional intake in an effort to cut down upon the intake of expensive meat or meat-based products. The result of course is a diet which does not have sufficient protein present and is therefore nutritionally deficient.
Because of the rising cost of meat and meat-based products and because of the real nutritional needs of many people which are not being satisfied, in recent years much work has been done in regard to preparing meat analog products. Meat analogs, or in other words synthetic meats, are advantageous when compared with natural meat products, not only from the standpoint of cost, but also from the standpoint of being low calorie and sometimes actually higher in protein content. Therefore, meat analogs can be made superior from the standpoint of nutrition as well as cost.
Currently, most meat analog products are made by two basic processes: that is, either fiber spinning or thermoplastic extrusion. The fiber spinning technique is an adaptation of the spun fiber method of making synthetic fibers utilized in the textile industry. In this method, fibrous protein products are prepared from proteins such as soy protein by forming a spinning dope from alkali-treated protein and extruding the dope through a perforated die or membrane into an aqueous precipitating bath which contains an acid and a salt. The acid bath sets the filaments or fibers which are formed in the bath. The filaments may be bundled together and stretched to orient the molecular structure of the fibers. For further details in regard to the fiber spinning technique, see the basic Boyer U.S. Pat. No. 2,682,466, issued June 29, 1954, which relates to spun fiber meat analogs. Other patents relating to such a process include Boyer et al., U.S. Pat. No. 2,730,448, issued Jan. 10, 1956, and Boyer, U.S. Pat. No. 2,730,447, also issued on Jan. 10, 1956.
The other principal method of forming meat analog products is by thermoplastics extrusion which is an adaptation of technology involved in making ready-to-eat cereal food products. The thermoplastic extrusion process involves preparing a mixture of protein, water, flavor, and other minors, and thereafter feeding the mixture into a cooker-extruder wherein it is subjected to heat and pressure, and subsequently extruding the mixture. The extrudate as it enters into the atmosphere expands to form what has been characterized as "meat-like" fibers. For examples of patents describing the thermoplastic extrusion techniques in forming meat analogs, see U.S. Pat. Nos. MacAllister et al., 3,102,031, issued Aug. 27, 1963, Atkinson, U.S. Pat. No. 3,488,770, issued Jan. 6, 1970, and British Pat. Nos. 1,174,906, published Dec. 17, 1969, and 1,105,904, published Mar. 13, 1968.
While both the fiber spinning technique adapted from the textile industry and the thermoplastic extrusion technique adapted from the ready-to-eat cereal industry have commonly been utilized to provide meat analog materials, it is generally recognized in the industry that the fiber spinning technique is most advantageous from the standpoint of forming actual meat-like fibers, However, the fiber spinning technique is quite expensive as well as complicated, and therefore the use of that technique tends to negate one of the primary purposes for forming meat analog products, i.e. an inexpensive meat substitute. Moreover, it is generally recognized by experts as well as consumers that neither of the above described processes actually produce a product which is meat-like in eating quality.
A third method of forming meat analog products which combines technology from both the spinning method and the extrusion method generally involves formation of a protein dough-like material and thereafter shaping the protein dough, and subsequently either forming layers of protein dough material or, in some cases utilizing a single layer and heating the dough-like material. Of course, the ultimate product prepared by this type of process has differing product characteristics, depending upon how, or whether, layers of material are laminated. For examples of this type of process see in particular two patents issued to Anson et al., U.S. Pat. Nos. 2,802,737 issued Aug 13, 1957, and 2,830,902, issued Apr. 15, 1958.
This process which combines technology from both the fiber spinning technique and the thermoplastic extrusion technique, cited by the Anson et al. patents, is notably deficient in producing a product which has meat-like eating quality. In other words, depending upon how the Anson et al. dough sheet is "sandwhiched", the product may have the appearance and texture of meat; however, when actually eaten the mouth feel, i.e. eating quality, is different from that of meat. Presumably this is so because of a lack of stringiness when eating the product.
While some of the prior art methods have allowed formation of a product which has an appearance and texture closely resembling that of ordinary meat products, there is no presently known meat analog product which duplicates the eating quality of actual meat as well as the texture and appearance. The term "eating quality" as utilized herein is intended to mean duplication of the mouth feel sensation obtained while eating meat. The eating quality of actual meat is described as "chewy" and "stringy" in nature. Since this chewiness and stringiness is associated with eating actual meats, if meat analogs are to be accepted it is evident that they also must be prepared in such a manner that they have chewiness and stringiness. Duplication of the actual eating quality of meat is hard because while fibers may be aligned unidirectionally and parallel, it is another matter to provide a sufficient amount of adhesiveness to allow the material to hold together so that it has the texture and appearance of meat and yet not have excessive adhesiveness which, because the fibers are not easily separated, destroys the stringy eating quality.
It is an object of this invention to provide meat analogs which resemble in appearance and texture natural meats, by a process which is especially economical in that it does not involve fiber spinning nor does it necessarily involve thermoplastic extrusion and by a process which is not limited to the utilization of heat-coagulable protein.
Additionally, it is an object of this invention to provide a process which not only duplicates meat in appearance as well as texture but which duplicates the actual eating quality of meat. The eating quality is duplicated by a process which involves binding individual fibers, preferably with an edible binder, such that there is provided adequate cohesiveness to hold the product in a coherent fiber mass, but not enough cohesiveness to destroy the mouth feel of striated meat-like fibers, i.e. meat eating quality.